I've seen these mistakes in codebases over and over again. Don't be that developer. Why JWT Gets Misused So Often JWT (JSON Web Tokens) looks simple on the surface. You generate a token, send it to the client, verify it on the server. Easy, right? Wrong. Most developers copy a tutorial, get it "working," and ship it to production without realizing they've left massive security holes open. I've been there too. Here are the 7 mistakes I see most often — and exactly how to fix them. Mistake #1 — Storing JWT in localStorage This is probably the most common mistake and one of the most dangerous. // ❌ WRONG — don't do this localStorage . setItem ( ' token ' , jwt ) Enter fullscreen mode Exit fullscreen mode Why it's dangerous: localStorage is accessible by any JavaScript on the page. If your app has even one XSS vulnerability, an attacker can steal every user's token in seconds. The fix: Store your JWT in an httpOnly cookie instead. JavaScript can't touch it. // ✅ CORRECT — set it server side res .…